I bough a "rosy" stone from the "French baker" (1stone in France). This turned out to be one of the best coticules i have tried.
When the seller/vendor provides photos, and you have an idea of what visual characteristics you are looking for it is less of a gable in my opinion.
My first La Grise from Ardennes was an ok stone, but it was difficult to use, and it does not have the same range and versatility as some other coticules i have.
I would not buy a standard or select grade again without actually seeing the stone beforehand.
All the select plus grade stones i bought have been exceptional.